Regular exercise and the practice of calorie restriction with optimal nutrition are both shown to extend life in laboratory animals, but only calorie restriction reliably extends maximum life span in addition to raising the average. Both exercise and calorie restriction are associated with a longer life expectancy in humans, and improve short-term measures of health in humans in the same way as in laboratory animals. On the other side of the scale, becoming fat and sedentary are shown to shorten life expectancy and make health worse in laboratory animals, and are associated with that same outcome in humans. The amount and quality of evidence for these points are the gold standard against which other claims about health practices should be measured.
No presently available technique or medical technology has been shown to do anywhere near as well as exercise and calorie restriction for a basically healthy individual: any responsible physician will tell you this. So don’t go hunting for silver bullets that don’t exist – there are always people out there willing to sell you a lie. It’s the sad truth that you can’t exercise your way to a 100% chance of living to 100: a majority of even the fittest people with the best diets die of old age and its complications before reaching 90 in the environment of today’s medical technology.
Medical technology is key. Progress in medical technology is the greatest determinant of how long you will live and how good your health will be when you are older. Thus the more you can do to speed development towards therapies capable of human rejuvenation the longer you will likely live, and this is something that we can all help with: learn which research should be supported, make donations, and persuade your friends. All of that exercise and calorie restriction is just there to raise the odds of living to see the day on which aging can be reversed. Without future advances in medicine, you’ll age and die on roughly the same schedule as your grandparents and great-grandparents regardless of how well you look after your health.